Quantity   Component name
1 × 5 way tactile switch https://www.sparkfun.com/products/10063
1 × ATmega32u4 Needed for the built in USB. This is the processor found on the Arduino Leonardo
1 × mini OLED display
1 × Serial flash memory Either SD card or memory IC
1 × AT88SC0204CA cryptographic memory Memory ICs / Other Memory ICs